Before asphalt was discovered to have useful properties, particularly as a water sealant for roofing applications and cementing material for pavement applications, asphalt was discarded as a waste product of petroleum. Today, however, asphalt is widely used in the construction industry, especially in the roofing and paving industries.
In addition to asphalt being a useful by-product of petroleum, asphalt demonstrates marked properties for being reusable. It does not deteriorate significantly over time and use, therefore, it can be reused numerous times by recycling, rejuvenating and reprocessing.
Environmental concerns of current times have commanded increased efficiency and awareness in recycling numerous types of materials and products. Asphalt, given its marked recyclability, is one such product. Many methods and apparatuses exist for manufacturing asphalt, for forming asphalt into asphalt products, for recycling asphalt from asphalt-containing materials, for recycling asphalt from reclaimed asphalt product refuse, such as roofing refuse, and for using recycled asphalt for construction repair and maintenance purposes.
U.S. Pat. No. 4,706,893 teaches a method and apparatus for recycling asphalt shingles by heating and drying aggregate in an asphalt plant, then mixing the heated and dried aggregate with liquid asphalt to form an asphalt paving composition. This patent discloses a process of shredding waste shingles into small pieces, feeding the pieces into a drying drum to melt them, adding liquid asphalt, then mixing the aggregate, shingle material and liquid asphalt thoroughly.
Another method and apparatus for recycling asphalt aggregate compositions is disclosed in U.S. Pat. No. Re. 31,904. This art teaches the use of asphalt aggregate crushed and metered into different sized pieces. Coarse and fine bits of asphalt aggregate are introduced into a rotatable drum where they are melted in a distinct heating zone of the drum. This patent teaches the reduction of pollution caused by overheating asphalt aggregate by controlling the heating process and, particularly, by concentrating heating of non-asphalt aggregate in a hot zone of the drum, and heating asphalt aggregate in a cooler zone of the drum.
Other patents focus on hot asphalt pavement mix. U.S. Pat. Nos. 4,540,287, 4,147,436 and 4,075,710 teach methods and apparatuses of recycling asphalt for producing hot asphalt mixes. Generally, this involves heating asphalt aggregate in a heating zone, and mixing the heated aggregate with reclaimed asphalt and a binder to produce hot asphalt pavement mix. These patents vary generally based upon the configuration of the heating drum, the zones within the drum, and the steps in the process for recycling the asphalt getting to and within the drum. See also U.S. Pat. Nos. 4,325,641, 4,177,080, 4,104,736, 3,999,743, and 3,975,002.
Cold patch compositions also are taught by the prior art. U.S. Pat. No. 3,930,000, for example, discloses an elastomeric cold patch for pavement repair comprised of asphalt aggregate and rubber. The asphalt is heated, then rubber is added to form a gel mixture, and then the mixture is allowed to cool. The resulting cold patch is applied by cleaning the area to be repaired and applying a substance to create a sticky surface, such as by hot asphalt, to which the cold patch sheet will stick.
Unlike the prior art, the present invention does not involve an asphalt heating process for producing asphalt products. Heating causes numerous manufacturing, energy resource and pollution complications. It also is more costly than the process and composition of the present invention. The present invention concentrates primarily on cold mix preparations of asphalt products from particulated asphalt, especially using recycled asphalt, for pavement construction, repair and maintenance of asphalt-containing products. The products of the present invention have primary applications in the construction industry, and differ from the prior art through the use of asphalt particles as opposed to liquid asphalt to form asphalt products.
It is therefore one object of the present invention to provide a composition for an asphalt product formed of asphalt particulate as opposed to liquid asphalt for construction, repair and maintenance of asphalt-containing products.
Another object of the present invention is to provide a composition for cold mix asphalt construction, repair and maintenance of asphalt-containing products which does not require heating of asphalt to produce the asphalt product.
Another object of the present invention is to provide a composition for asphalt product used to construct, repair or maintain other asphalt-containing products in the construction industry using recycled asphalt particulate.
Another object of the present invention is to provide a composition for recycled asphalt product used to construct, repair or maintain other asphalt-containing products in the pavement industry using asphalt particulate formed from recycled asphalt.
Yet another object of the present invention is to provide a composition for asphalt product used to construct, repair or maintain various pavement and roadway articles using asphalt particulate formed from recycled asphalt obtained from roofing refuse.
Still another object of the present invention is to provide a process for producing an asphalt product for construction, repair and maintenance of asphalt-containing products, particularly in the construction industry, using particulated asphalt as opposed to liquid asphalt.
Another object of the present invention is to provide a process for producing a recycled asphalt product for construction, repair and maintenance using particulated asphalt from recycled asphalt-containing materials and, in particular, roofing refuse.
Yet another object of the present invention is to provide a composition and process for construction, repair and maintenance of products using recycled asphalt-containing materials and, in particular, roofing refuse, without the use of high-energy, high-polluting devices such as hot mix compositions and processes currently available.
These and other objects, features and advantages of the present invention will become apparent from the following description when considered in connection with the accompanying examples.